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Poster: Eric_Petersen Date: Mar 31, 2005 2:55am
Forum: prelinger Subject: Video encoding question

Hi, Folks -

As someone well versed in MPEG-1 and MPEG-2 video encoding, I was wondering why many films here are not encoded to the proper standards. While the standards don't matter to those with newer DVD players, the films will not play on older ones because they are not encoded the standard way. The standards are as follows:

MPEG-1 (VCD) - 352x240 resolution, 29.97fps, (or 23.976fps film) 1150kbps bitrate

MPEG-2 (SVCD) - 480x480 resolution, 29.97 fps, (or 23.976fps film) 2520kbps bitrate (variable)

I've seen many of your MPEG-1 files encoded at below standard resolution - 320x240 - and many MPEG-2 files are encoded non-standard as well, with resolutions as high as 704x480 but with a low 1150kbps bitrate, which results in a larger file, but no better picture quality than MPEG-2 SVCD standard. With the standard, you can keep the 480x480 resolution and tweak the bitrate to get a smaller-size file, but retain the quality. You can also reduce the file size by taking the audio bitrate down to 64kbps, which has pretty much the same sound quality as the normal rate of 224kbps.

As for MPEG-1, (VCD) you can't tweak anything and stay standard, but a decent video encoder like Tmpgenc - which is freeware for MPEG-1 only - can make great quality MPEG-1 files that will look good on any DVD player or PC. Just select Highest Quality for Motion Search Precision speed. It will take longer to encode but it will be worth it - the final product will not be as blocky, especially if you tick the Soften Block Noise box.

One more encoding suggestion: raise the volume. Some movie files have such low volume that you have to jack the TV or PC volume way up to hear them.

For those of you want to burn your files on DVDs instead of CDs, the SVCD standard is MPEG-2, which is the same format as DVD.

Fortunately for me, I have a cable modem. Downloading big files is no problem. But those on dial-up can't be expected to download 15-minute movies that are 700MB in length, especially with no MPEG-1 version available for many movies. (Unless they want the yucky ultra-low resolution MPEG-4 files) That's a pity, because the films offered here at Archive.Org are all treasures. Keep up the fantastic work!

- Eric Petersen

This post was modified by Eric_Petersen on 2005-03-31 10:55:08

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Poster: Steve Nordby Date: Mar 31, 2005 10:32am
Forum: prelinger Subject: Re: Video encoding question

"Standards" is the word that matters here, and yes, 352x240 is *a* standard for NTSC mpeg1 and 480x480 is *a* standard for mpeg2, they are hardly the only ones. 320x240 *is* the standard for mpeg1 displayed on a computer. 704x480 is one of several mpeg2 standards for DVD. Dozens more standards discussed here: http://www.iki.fi/znark/video/conversion/

This post was modified by Steve Nordby on 2005-03-31 18:32:47